Working fluid composition for refrigerator

Abstract

The present invention provides a working fluid composition for a refrigerating machine, comprising: a refrigerating machine oil comprising, as a base oil, a mixed ester of (A) a complex ester obtainable by synthesis of at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a C6-C12 polybasic acid, and a C4-C18 monohydric alcohol or a C4-C18 monocarboxylic fatty acid, and (B) a polyol ester obtainable by synthesis of from at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol, and a C4-C18 monocarboxylic fatty acid, in a mass ratio of (A) the complex ester / (B) the polyol ester of 5 / 95 to 95 / 5; and tetrafluoropropene as a refrigerant, wherein a refrigerant dissolved viscosity, at a temperature of 80° C. and an absolute pressure of 1.6 MPa, is 1.5 mm2 / s or more.

Description

TECHNICAL FIELD[0001]The present invention relates to a working fluid composition for a refrigerating machine. It is noted that the term “refrigerating machine” herein embraces a vehicle air conditioner, a dehumidifier, a refrigerator, a refrigerated warehouse, a cooling apparatus used in a vending machine, a showcase, a chemical plant or the like, a household air conditioner, a package air conditioner, a heat pump for hot water supply, and the like.BACKGROUND ART[0002]In the field of refrigeration and air conditioning, 1,1,1,2-tetrafluoroethane (R134a) that is a hydrofluorocarbon (HFC) and R410A that is a mixed refrigerant of difluoromethane (R32) and pentafluoroethane (R125) in a mass ratio of 1 / 1 are currently widely used as refrigerants for a refrigerator, a car air conditioner, a room air conditioner, industrial refrigerating machine, and the like. Although such HFC refrigerants have an ozone depletion potential (ODP) of zero, they have a high global warming potential (GWP) of ...